This invention relates generally to couplings for conduits that convey fluids such as liquids and gases, and more particularly concerns a system for achieving fluid-tight joinder of the non-threaded ends of two cylindrical tubes or pipes.
In the case of surface irrigation pipelines, it is often necessary to rapidly couple and uncouple pipe sections without the benefit of tools, and further enable the pipeline to be contoured around obstacles or to conform with the terrain it interacts with. Pipe sections leading to irrigation system sprinkler heads must also be amenable to quick coupling and positioned adjustability relative to other portions of the pipeline.
Coupling systems for tubes and pipes are well known. However, many such systems require the use of tools or depend upon threaded fittings which, in irrigation systems, are difficult to maintain clean. Other coupling systems necessitate straight line coaxial engagement of the pipe segments without permitting any angular deflection at the joint.
In certain earlier disclosed rapidly activated coupling devices, a resilient flap is employed which, under hydraulic pressure, is displaced against a seating member, thereby forming a sealed juncture. The uncoupling of such devices can be extremely difficult in field use especially when the conduits still contain pressurized fluid. In other rapid coupling devices, the conduits are brought together in the axial direction with sufficient manually applied force to compress a resilient gasket which thereby produces a sealed juncture. Such coupling devices, requiring manual compressive force, generally involved multi-component lever mechanisms that are difficult to manipulate and require external pivot means susceptible to malfunction after extensive use and outdoor exposure.
A problem generally associated with quick acting coupling devices is that, after considerable use, wear and erosion of critically dimensioned components causes malfunction. In conduit systems handling corrosive liquids, it is sometimes desirable to be able to drain the system of stagnent fluid when not in use, especially at the couplings, in order to minimize corrosive damage. Most coupling devices are not able to permit controlled draining while still engaging the conduits.
It is accordingly an object of the present invention to provide a conduit coupling which is quickly operable without tools.
It is a further object of this invention to provide a coupling as in the foregoing object which permits leak-free joinder of the ends of two conduits that may not be in coaxial alignment.
It is another object of this invention to provide a coupling of the aforesaid nature which compensates for wear and permits controlled drainage.
It is still another object of the present invention to provide a coupling of the aforesaid nature of rugged, durable construction amenable to low cost manufacture.
These objects and other objects and advantages of the invention will be apparent from the following description.